1. Field of the Invention
This invention relates to a shooting game machine, and more particularly to a shooting game machine for shooting a target using a light beam.
2. Description of the Related Art
Conventionally shooting game machines are known which employs a light beam gun or the like. This conventional type shooting game machine is disclosed in Japanese Patent Laid-Open Publications Nos. Sho 50-72515, Sho 60-179079 and Hei 4-51987.
In this conventional art, the light beam gun is fired at a screen on which a target is displayed, and an impact position of the light beam is photographed using a video camera. It was however impossible to locate the impact position of the light beam precisely and simply.
For example, in the shooting game machine of Japanese Patent Laid-Open Publication No. Sho 50-72515, the impact position of the light beam gun is projected on a predetermined target board via a half-transmissive mirror, and this impact position is photographed by the video camera and is displayed on a display storage tube. A target described on the target board is superimposed on the screen of the display storage tube via the half-transmissive mirror, thereby synthesizing an image of a bullet mark, which represents the impact position, with the target. In this conventional machine, the impact beam point of the light beam gun is only photographed by the video camera, and no impact position is detected.
In the shooting game machine of Japanese Patent Laid-Open Publication No. Sho 60-179079, a shooting video image, in which a predetermined target appears, is projected on a screen using a projector, and the player may shoot the projected target by a light beam gun. The impact position is detected by photographing the screen by a video camera, and discrimination is made as to whether the shot has hit the target or has missed the target.
However, in this conventional machine, the image displaying operation of an image forming CRT mounted in the projector and the photographing operation of the television camera for photographing the screen have to be perfectly synchronized. A picture signal output from the television camera for its every horizontal scanning is compared with a target position display signal, which is read from a ROM in synchronism with the horizontal scanning, by a comparator to discriminate whether or not the beam point of the light beam gun is within the display area of the target, thereby detecting whether the shot has hit or missed the target. Thus, in this conventional machine, since the camera and the CRT have to be perfectly synchronized with each other in order to detect the impact position of the light beam gun, the setting-up therefor is meticulous.
In particular, since the output signal of the video camera and the impact position display signal, which is read from the ROM storing video information, have to be compared, for every horizontal scanning, in order to discriminate whether or not the shot has hit the target, it requires a complicated and expensive circuit.
Japanese Patent Laid-Open Publication No. Hei 4-51987 discloses the concept of displaying the entire screen using a CCD camera and detecting the impact position of the light beam gun based on a signal output from the CCD camera, but is totally silent about how to detect the impact position.